Wireless LANs have been developed and are now used in offices, retail stores and large industrial facilities, such as warehouses and factories. These LANs provide data communication between computers, printers, servers and other devices without the trouble and expense of installing wires and cables. In addition to data communication, some LANs provide voice communication between devices on the LAN. Systems are also available that permit the LAN to communicate with a remote device using a telephone connection.
A problem with telephone communication from a LAN is the limited functionality of the phone. A LAN phone does not provide the voice mail, caller ID and other functionality of a PBX system that have become indispensable to users of office telephone systems. Thus, because of the limited functionality of a LAN phone system, another telephone system such as a PBX is required.